Surgical stapling instrument having a single lockout mechanism for prevention of firing

ABSTRACT

A surgical instrument for laparoscopic and endoscopic clinical procedures simultaneously severs and staples tissue clamped in an end effector comprising an elongate channel, which holds a staple cartridge, and a pivotally attached anvil. An E-beam firing bar engages the channel and selectively engages the anvil during distal firing movements, wherein the tissue is severed and stapled driven upward from the staple cartridge to form against the anvil. In particular, a wedge integral to the staple cartridge is driven distally by a middle pin of the firing bar to effect stapling. A single lockout of the elongate channel responds to the presence of the wedge sled in its unfired position to allow the firing bar to fire. Otherwise, the single lockout prevents firing when the staple cartridge is missing or spent.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application is related to four co-pending andcommonly-owned applications filed on even date herewith, the disclosureof each is hereby incorporated by reference in their entirety, thesefour applications being respectively entitled:

[0002] (1) “SURGICAL STAPLING INSTRUMENT HAVING A FIRING LOCKOUT FOR ANUNCLOSED ANVIL” to Frederick E. Shelton IV, Mike Setser, and BruceWeisenburgh;

[0003] (2) “SURGICAL STAPLING INSTRUMENT HAVING SEPARATE DISTINCTCLOSING & FIRING SYSTEMS” to Frederick E. Shelton, Mike Setser, andBrian J. Hemmelgam;

[0004] (3) “SURGICAL STAPLING INSTRUMENT HAVING A SPENT CARTRIDGELOCKOUT” to Frederick E. Shelton IV, Mike Setser, Bruce Weisenburgh; and

[0005] (4) “SURGICAL STAPLING INSTRUMENT INCORPORATING AN E-BEAM FIRINGMECHANISM” to Frederick E. Shelton IV, Mike Setser, and BruceWeisenburgh.

FIELD OF THE INVENTION

[0006] The present invention relates in general to surgical staplerinstruments that are capable of applying lines of staples to tissuewhile cutting the tissue between those staple lines and, moreparticularly, to improvements relating to stapler instruments andimprovements in processes for forming various components of such staplerinstruments.

BACKGROUND OF THE INVENTION

[0007] Surgical staplers have been used in the prior art tosimultaneously make a longitudinal incision in tissue and apply lines ofstaples on opposing sides of the incision. Such instruments commonlyinclude a pair of cooperating jaw members that, if the instrument isintended for endoscopic or laparoscopic applications, are capable ofpassing through a cannula passageway. One of the jaw members receives astaple cartridge having at least two laterally spaced rows of staples.The other jaw member defines an anvil having staple-forming pocketsaligned with the rows of staples in the cartridge. The instrumentincludes a plurality of reciprocating wedges which, when drivendistally, pass through openings in the staple cartridge and engagedrivers supporting the staples to effect the firing of the staplestoward the anvil.

[0008] An example of a surgical stapler suitable for endoscopicapplications is described in U.S. Pat. No. 5,465,895, whichadvantageously provides distinct closing and firing actions. Thereby, aclinician is able to close the jaw members upon tissue to position thetissue prior to firing. Once the clinician has determined that the jawmembers are properly gripping tissue, the clinician can then fire thesurgical stapler, thereby severing and stapling the tissue. Thesimultaneous severing and stapling avoids complications that may arisewhen performing such actions sequentially with different surgical toolsthat respectively only sever or staple.

[0009] It is often advantageous to build an end effector for thesurgical stapler that is reusable. For instance, one patient may need aseries of severing and stapling operations. Replacing an entire endeffector for each operation tends to be economically inefficient. Thisis especially true if the end effector is built to be strong andreliable over repeated operations. To that end, staple cartridges arefitted into the end effector prior to each operation of the surgicalstapler. Thus, a much smaller amount of the surgical staples isdiscarded after each use.

[0010] While the staple cartridge provides numerous advantages, it isdesirable to prevent inadvertent firing of the surgical stapler when anunfired staple cartridge is not present. Otherwise, the severing oftissue may occur without the staples to minimize bleeding.

[0011] It is particularly desirable that preventing such inadvertentfiring be accomplished in a reliable way that is not subject to anintervening malfunction. Moreover, for ease of manufacturing andassembly, it is further desirable that the lockout features beaccomplished with a minimum number of components.

[0012] Consequently, a significant need exists for an improved surgicalstapling and severing instrument that prevents inadvertent firing (i.e.,severing and stapling) when a staple cartridge is not installed or isspent, having been previously fired.

BRIEF SUMMARY OF THE INVENTION

[0013] The invention overcomes the above-noted and other deficiencies ofthe prior art by providing a single lockout mechanism that preventsfiring a surgical stapling and severing instrument when either a staplecartridge is not installed or is spent. In particular, the single lockmechanism prevents distal movement of a firing bar, and thus severing oftissue, in instances where simultaneous stapling would not occur.

[0014] In one aspect of the invention, a surgical instrument includes ahandle portion operable to produce a firing motion that actuates animplement portion. This implement portion has an elongate channel thatreceives a staple cartridge with a firing drive slot definedtherebetween. A firing mechanism engages the elongate channel along itslongitudinal length and includes an engaging device that traverses thefiring drive slot for distally moving a wedge sled in the staplecartridge. A lockout mechanism is advantageously positioned to be movedout of the firing drive slot by the presence of the wedge sled in itsunfired, proximal position, and thus allowing the firing bar to fire.When the wedge sled is no longer in the unfired position (i.e., spentcartridge or missing cartridge), the lockout mechanism resiliently movesinto the firing drive slot. The proximal and distal sides of the lockoutmechanism present in the firing drive slot are shaped to allow theengaging device of the firing bar to return to its proximal, initialposition but to thereafter impede distal movement until an unfiredstaple cartridge is installed.

[0015] These and other objects and advantages of the present inventionshall be made apparent from the accompanying drawings and thedescription thereof.

BRIEF DESCRIPTION OF THE FIGURES

[0016] The accompanying drawings, which are incorporated in andconstitute a part of this specification, illustrate embodiments of theinvention, and, together with the general description of the inventiongiven above, and the detailed description of the embodiments givenbelow, serve to explain the principles of the present invention.

[0017]FIG. 1 depicts a partially cut-away side elevation view of asurgical stapling and severing instrument in an open position.

[0018]FIG. 2 depicts a cross-sectional side elevation detail view alongthe line 2-2 of FIG. 1 of an end effector of the surgical stapling andsevering instrument.

[0019]FIG. 3 depicts an enlarged side elevation view of the firing barof the surgical stapling and severing instrument of FIG. 2.

[0020]FIG. 4 depicts an enlarged front view of the firing bar of thesurgical stapling and severing instrument of FIG. 2.

[0021]FIG. 5 depicts a cross-sectional side elevation detail view of analternative end effector for the surgical stapling and severinginstrument of FIG. 1, incorporating a firing bar that lacks a middle pinfor preventing pinching of the end effector.

[0022]FIG. 6 depicts a side elevational view of a handle portion of aproximal end of the surgical stapling and severing instrument of FIG. 1with a left side removed to expose interior parts in an unclamped,unfired (“start”) position.

[0023]FIG. 7 depicts a perspective, exploded view of the handle portionof the proximal end of the surgical stapling and severing instrument ofFIG. 1.

[0024]FIG. 8 depicts a side elevational view of the handle portion ofthe proximal end of the surgical stapling and severing instrument ofFIG. 1 with the left side removed to expose interior parts in the closed(“clamped”) position.

[0025]FIG. 9 depicts a side elevational view of the handle portion ofproximal end of surgical stapling and severing instrument of FIG. 1 withthe left side removed to expose interior parts in the stapled andsevered (“fired”) position.

[0026]FIG. 10 depicts an isometric view of the end effector at thedistal end of the surgical stapling and severing instrument of FIG. 1with the anvil in the up or open position exposing the staple cartridgeand cutting edge of the firing bar.

[0027]FIG. 11 depicts an isometric, exploded view of the implementportion of the surgical stapling and severing instrument of FIG. 1.

[0028]FIG. 12 depicts an isometric view of the end effector at thedistal end of the surgical stapling and severing instrument of FIG. 1with the anvil in the up or open position with the cartridge largelyremoved exposing a single staple driver and a double staple driver asexemplary and the wedge sled in its start position against a middle pinof the firing bar.

[0029]FIG. 13 depicts an isometric view of the distal end of thesurgical stapling and severing instrument of FIG. 1 with the anvil inthe up or open position with the staple cartridge completely removed anda portion of an elongate channel removed to expose a lowermost pin ofthe firing bar.

[0030]FIG. 14 depicts a side elevation view in section showing amechanical relationship between the anvil, elongate channel, and staplecartridge in the closed position of the surgical stapling and severinginstrument of FIG. 1, the section generally taken along lines 14-14 ofFIG. 10 to expose wedge sled, staple drivers and staples but alsodepicting the firing bar along the longitudinal centerline.

[0031]FIG. 15 depicts a section view of the end effector of the surgicalstapling and severing instrument with the cartridge and firing bar inthe start position taken along line 15-15 of FIG. 10.

[0032]FIG. 16 depicts a section view taken along line 16-16 of FIG. 15showing the cross-sectional relationship between the firing bar,elongate channel, wedge sled, staple drivers, staples and staplecartridge.

[0033]FIG. 17 depicts a side elevation section view of the surgicalstapling and severing instrument of FIG. 1 taken along the longitudinalcenterline of the end effector in a partially closed but unclampedposition gripping tissue.

[0034]FIG. 18 depicts a partially cut-away side elevational view of thesurgical stapling and severing instrument of FIG. 1 in the closed orclamped position.

[0035]FIG. 19 depicts a side elevation view in centerline section of thedistal end of the surgical stapling and severing instrument of FIG. 1 inthe closed or clamped position with tissue properly compressed.

[0036]FIG. 20 depicts a partially cut-away side elevation view of thesurgical stapling and severing instrument of FIG. 1 in a partially firedposition.

[0037]FIG. 21 depicts a view in centerline section of the distal end ofthe surgical stapling and severing instrument of FIG. 1 in a partiallyfired position.

[0038]FIG. 22 depicts a partially cut-away side elevation view of thesurgical stapling and severing instrument of FIG. 1 in a fully firedposition.

[0039]FIG. 23 depicts a view in centerline section of the distal end ofthe surgical stapling and severing instrument of FIG. 1 in a fully firedposition.

[0040]FIG. 24 depicts a perspective view looking distally at theelongate channel of FIG. 1 partially cut away to expose a cartridge bodyand a single lockout mechanism engaging a middle pin of a firing bar.

[0041]FIGS. 25-28 depict a cross-sectional side detail view of thesingle lockout mechanism, staple cartridge and firing bar of FIG. 24,sequentially shown in a cartridge loaded and unfired state in FIG. 25, acartridge being fired state in FIG. 26, a spent cartridge with firingbar being retracted state in FIG. 27, and spent cartridge with firingbar retracted state in FIG. 28.

[0042]FIG. 29 depicts the single lockout mechanism of FIG. 24 furtherincorporating a lockout trough.

[0043]FIG. 30 depicts a bottom perspective view of an elongate channelof FIG. 1 partially cut away to show another single lockout mechanismengaging the middle pin of a firing bar when a staple cartridge ismissing.

[0044]FIGS. 31-34 depict a cross-sectional side detail view of thesingle lockout mechanism of FIG. 30, sequentially shown in a cartridgeloaded and unfired state in FIG. 31, a cartridge being fired state inFIG. 32, a spent cartridge with firing bar being retracted state in FIG.33, and a spent cartridge with firing bar retracted state in FIG. 34.

DETAILED DESCRIPTION OF THE INVENTION

[0045] Turning to the Drawings, wherein like numerals denote likecomponents throughout the several views, FIG. 1 and 2 depict a surgicalstapling and severing instrument 10 that is capable of practicing theunique benefits of the present invention. The surgical stapling andsevering instrument 10 incorporates an end effector 12 having an E-beamfiring mechanism (“firing bar”) 14 that advantageously controls thespacing of the end effector 12. In particular, an elongate channel 16and a pivotally translatable anvil 18 are maintained at a spacing thatassures effective stapling and severing. Furthermore, firing (i.e.,severing and stapling) is prevented from occurring if the instrument isnot capable of stapling with a single lockout mechanism, which isdescribed in more detail below.

[0046] The surgical and stapling and severing instrument 10 includes ahandle portion 20 connected to an implement portion 22, the latterfurther comprising a shaft 23 distally terminating in the end effector12. The handle portion 20 includes a pistol grip 24 toward which aclosure trigger 26 is pivotally drawn by the clinician to causeclamping, or closing, of the anvil 18 toward the elongate channel 16 ofthe end effector 12. A firing trigger 28 is farther outboard of theclosure trigger 26 and is pivotally drawn by the clinician to cause thestapling and severing of clamped tissue in the end effector 12.

[0047] It will be appreciated that the terms “proximal” and “distal” areused herein with reference to a clinician gripping a handle of aninstrument. Thus, the end effector 12 is distal with respect to the moreproximal handle portion 20. It will be further appreciated that forconvenience and clarity, spatial terms such as “vertical” and“horizontal” are used herein with respect to the drawings. However,surgical instruments are used in many orientations and positions, andthese terms are not intended to be limiting and absolute.

[0048] Closure trigger 26 is actuated first. Once the clinician issatisfied with the positioning of the end effector 12, the clinician maydraw back the closure trigger 26 to its fully closed, locked positionproximate to the pistol grip 24. Then, the firing trigger 28 isactuated. The firing trigger 28 springedly returns when the clinicianremoves pressure. A release button 30 when depressed on the proximal endof the handle portion 20 releases any locked closure trigger 26.

[0049] A closure sleeve 32 encloses a frame 34, which in turn encloses afiring drive member 36 that is positioned by the firing trigger 28. Theframe 34 connects the handle portion 20 to the end effector 12. With theclosure sleeve 32 withdrawn proximally by the closure trigger 26 asdepicted, the anvil 18 springedly opens, pivoting away from the elongatechannel 16 and translating proximally with the closure sleeve 32.

[0050] The elongate channel 16 receives a staple cartridge 37 that isresponsive to the firing bar 14 to drive staples into forming contactwith the anvil 18. It will appreciated that although a readilyreplaceable staple cartridge 37 is advantageously described herein, astaple cartridge 37 consistent with aspects of the present invention maybe permanently affixed or integral to the elongate channel 16, forinstance when a larger portion of the end effector 12 is replaced aftereach firing.

[0051] E-Beam Firing Mechanism

[0052] With particular reference to FIGS. 2-4, the firing bar 14includes three vertically spaced pins that control the spacing of theend effector 12 during firing. In particular, an upper pin 38 is stagedto enter an anvil pocket 40 near the pivot between the anvil 18 andelongate channel 16. When fired with the anvil 18 closed, the upper pin38 advances distally within a longitudinal anvil slot 42 extendingdistally through anvil 18. Any minor upward deflection in the anvil 18is overcome by a downward force imparted by the upper pin 38.

[0053] Firing bar 14 also includes a lower most pin, or firing bar cap,44 that upwardly engages a channel slot 45 in the elongate channel 16,thereby cooperating with the upper pin 38 to draw the anvil 18 and theelongate channel 16 slightly closer together in the event of excesstissue clamped therebetween.

[0054] The firing bar 14 advantageously includes a middle pin 46 thatpasses through a firing drive slot 47 formed in a lower surface of thecartridge 37 and an upward surface of the elongate channel 16, therebydriving the staples therein as described below. The middle pin 46, bysliding against the elongate channel 16, advantageously resists anytendency for the end effector 12 to be pinched shut at its distal end.To illustrate an advantage of the middle pin 46, FIG. 5 depicts analternative end effector 12′ that lacks a middle pin on a firing bar14′. In this depiction, the end effector 12′ is allowed to pinch shut atits distal end, which tends to impair desired staple formation.

[0055] Returning to FIGS. 2-4, a distally presented cutting edge 48between the upper and middle pins 38, 46 on the firing bar 14 traversesthrough a proximally presented, vertical slot 49 in the cartridge 37 tosever clamped tissue. The affirmative positioning of the firing bar 14with regard to the elongate channel 16 and anvil 18 assure that aneffective cut is performed.

[0056] Cambered Anvil with Selected Cartridge Gap

[0057] The affirmative vertical spacing provided by the E-Beam firingbar 14 is suitable for the limited size available for endoscopicdevices. Moreover, the E-Beam firing bar 14 enables fabrication of ananvil 16 with a camber imparting a vertical deflection at its distalend, similar to the position depicted in FIG. 5. This cambered anvil 16advantageously assists in achieving the desired gap in the end effector12 even with an anvil 16 reduced thickness, which is thus more suited tothe size limitations of an endoscopic device.

[0058] The E-Beam firing bar 14 further enables increased applications,especially in combination with a range of configurations of staplecartridges. For instance, a clinician may select a gray staple cartridgeyielding a 0.02 mm tissue gap, a white staple cartridge yielding a 0.04mm tissue gap, a blue cartridge yielding a 0.06 mm tissue gap, or agreen cartridge yielding a 0.10 mm tissue gap. The vertical height ofeach respective staple cartridge in combination with the length ofstaples and an integral wedge sled (described in more detail below)predetermines this desired tissue thickness with the anvil 18appropriately vertically spaced by the E-Beam firing bar 14.

[0059] Two-Axis Handle

[0060] With reference to FIGS. 6-9, the handle portion 20 is comprisedof first and second base sections 50 and 52, which are molded from apolymeric material such as a glass-filled polycarbonate. The first basesection 50 is provided with a plurality of cylindrical-shaped pins 54.The second base section 52 includes a plurality of extending members 56,each having a hexagonal-shaped opening 58. The cylindrical-shaped pins54 are received within the hexagonal-shaped openings 58 and arefrictionally held therein for maintaining the first and second basesections 50 and 52 in assembly.

[0061] A rotating knob 60 has a bore 62 extending completely through itfor engaging and rotating the implement portion 22 about itslongitudinal axis. The rotating knob 60 includes an inwardly protrudingboss 64 extending along at least a portion of the bore 62. Theprotruding boss 64 is received within a longitudinal slot 66 formed at aproximal portion of the closure sleeve 32 such that rotation of therotating knob 60 effects rotation of the closure sleeve 32. It will beappreciated that the boss 64 further extends through frame 34 and intocontact with a portion of the firing drive member 36 to effect theirrotation as well. Thus, the end effector 12 (not shown in FIGS. 6-9)rotates with the rotating knob 60.

[0062] A proximal end 68 of the frame 34 passes proximally through therotating knob 60 and is provided with a circumferential notch 70 that isengaged by opposing channel securement members 72 extending respectivelyfrom the base sections 50 and 52. Only the channel securement member 72of the second base section 52 is shown. The channel securement members72 extending from the base sections 50, 52 serve to secure the frame 34to the handle portion 20 such that the frame 34 does not movelongitudinally relative to the handle portion 20.

[0063] The closure trigger 26 has a handle section 74, a gear segmentsection 76, and an intermediate section 78. A bore 80 extends throughthe intermediate section 78. A cylindrical support member 82 extendingfrom the second base section 52 passes through the bore 80 for pivotablymounting the closure trigger 26 on the handle portion 20. A secondcylindrical support member 83 extending from the second base section 52passes through a bore 81 of firing trigger 28 for pivotally mounting onthe handle portion 20. A hexagonal opening 84 is provided in thecylindrical support member 83 for receiving a securement pin (not shown)extending from the first base section 50.

[0064] A closure yoke 86 is housed within the handle portion 20 forreciprocating movement therein and serves to transfer motion from theclosure trigger 26 to the closure sleeve 32. Support members 88extending from the second base section 52 and securement member 72,which extends through a recess 89 in the yoke 86, support the yoke 86within the handle portion 20.

[0065] A proximal end 90 of the closure sleeve 32 is provided with aflange 92 that is snap-fitted into a receiving recess 94 formed in adistal end 96 of the yoke 86. A proximal end 98 of the yoke 86 has agear rack 100 that is engaged by the gear segment section 76 of theclosure trigger 26. When the closure trigger 26 is moved toward thepistol grip 24 of the handle portion 20, the yoke 86 and, hence, theclosure sleeve 32 move distally, compressing a spring 102 that biasesthe yoke 86 proximally. Distal movement of the closure sleeve 32 effectspivotal translation movement of the anvil 18 distally and toward theelongate channel 16 of the end effector 12 and proximal movement effectsclosing, as discussed below.

[0066] The closure trigger 26 is forward biased to an open position by afront surface 130 interacting with an engaging surface 128 of the firingtrigger 28. Clamp first hook 104 that pivots top to rear in the handleportion 20 about a pin 106 restrains movement of the firing trigger 28toward the pistol grip 24 until the closure trigger 26 is clamped to itsclosed position. Hook 104 restrains firing trigger 28 motion by engaginga lockout pin 107 in firing trigger 28. The hook 104 is also in contactwith the closure trigger 26. In particular, a forward projection 108 ofthe hook 104 engages a member 110 on the intermediate section 78 of theclosure trigger 26, the member 110 being outward of the bore 80 towardthe handle section 74. Hook 104 is biased toward contact with member 110of the closure trigger 26 and engagement with lockout pin 107 in firingtrigger 28 by a release spring 112. As the closure trigger 26 isdepressed, the hook 104 is moved top to rear, compressing the releasespring 112 that is captured between a rearward projection 114 on thehook 104 and a forward projection 116 on the release button 30.

[0067] As the yoke 86 moves distally in response to proximal movement ofthe closure trigger 26, an upper latch arm 118 of the release button 30moves along an upper surface 120 on the yoke 86 until dropping into anupwardly presented recess 122 in a proximal, lower portion of the yoke86. The release spring 112 urges the release button 30 outward, whichpivots the upper latch arm 118 downwardly into engagement with theupwardly presented recess 122, thereby locking the closure trigger 26 ina tissue clamping position, such as depicted in FIG. 8.

[0068] The latch arm 118 can be moved out of the recess 122 to releasethe anvil 18 by pushing the release button 30 inward. Specifically, theupper latch arm 118 pivots upward about pin 123 of the second basesection 52. The yoke 86 is then permitted to move proximally in responseto return movement of the closure trigger 26.

[0069] A firing trigger return spring 124 is located within the handleportion 20 with one end attached to pin 106 of the second base section52 and the other end attached to a pin 126 on the firing trigger 28. Thefiring return spring 124 applies a return force to the pin 126 forbiasing the firing trigger 28 in a direction away from the pistol grip24 of the handle portion 20. The closure trigger 26 is also biased awayfrom pistol grip 24 by engaging surface 128 of firing trigger 28 biasingfront surface 130 of closure trigger 26.

[0070] As the closure trigger 26 is moved toward the pistol grip 24, itsfront surface 130 engages with the engaging surface 128 on the firingtrigger 28 causing the firing trigger 28 to move to its “firing”position. When in its firing position, the firing trigger 28 is locatedat an angle of approximately 45° to the pistol grip 24. After staplefiring, the spring 124 causes the firing trigger 28 to return to itsinitial position. During the return movement of the firing trigger 28,its engaging surface 128 pushes against the front surface 130 of theclosure trigger 26 causing the closure trigger 26 to return to itsinitial position. A stop member 132 extends from the second base section52 to prevent the closure trigger 26 from rotating beyond its initialposition.

[0071] The surgical stapling and severing instrument 10 additionallyincludes a reciprocating section 134, a multiplier 136 and a drivemember 138. The reciprocating section 134 comprises a wedge sled in theimplement portion 22 (not shown in FIG. 6-9) and a metal drive rod 140.

[0072] The drive member 138 includes first and second gear racks 141 and142. A first notch 144 is provided on the drive member 138 intermediatethe first and second gear racks 141, 142. During return movement of thefiring trigger 28, a tooth 146 on the firing trigger 28 engages with thefirst notch 144 for returning the drive member 138 to its initialposition after staple firing. A second notch 148 is located at aproximal end of the metal drive rod 140 for locking the metal drive rod140 to the upper latch arm 118 of the release button 30 in its unfiredposition.

[0073] The multiplier 136 comprises first and second integral piniongears 150 and 152. The first integral pinion gear 150 is engaged with afirst gear rack 154 provided on the metal drive rod 140. The secondintegral pinion gear 152 is engaged with the first gear rack 141 on thedrive member 138. The first integral pinion gear 150 has a firstdiameter and the second integral pinion gear 152 has a second diameterwhich is smaller than the first diameter.

[0074]FIGS. 6, 8 and 9 depict respectively the handle portion 20 in thestart position (open and unfired), a clamped position (closed andunfired) and a fired position. The firing trigger 28 is provided with agear segment section 156. The gear segment section 156 engages with thesecond gear rack 142 on the drive member 138 such that motion of thefiring trigger 28 causes the drive member 138 to move back and forthbetween a first drive position, shown in FIG. 8, and a second driveposition, shown in FIG. 9. In order to prevent staple firing beforetissue clamping has occurred, the upper latch arm 118 on the releasebutton 30 is engaged with the second notch 148 on the drive member 138such that the metal drive rod 140 is locked in its proximal-mostposition, as depicted in FIG. 6. When the upper latch arm 118 falls intothe recess 122, the upper latch arm 118 disengages with the second notch148 to permit distal movement of the metal drive rod 140, as depicted inFIG. 9.

[0075] Because the first gear rack 141 on the drive member 138 and thegear rack 154 on the metal drive rod 140 are engaged with the multiplier136, movement of the firing trigger 28 causes the metal drive rod 140 toreciprocate between a first reciprocating position, shown in FIG. 8, anda second reciprocating position, shown in FIG. 9. Since the diameter ofthe first pinion gear 150 is greater than the diameter of the secondpinion gear 152, the multiplier 136 moves the reciprocating section 134a greater distance than the drive member 138 is moved by the firingtrigger 28. The diameters of the first and second pinion gears 150 and152 may be changed to permit the length of the stroke of the firingtrigger 28 and the force required to move it to be varied.

[0076] It will be appreciated that the handle portion 20 is illustrativeand that other actuation mechanisms may be employed. For instance, theclosing and firing motions may be generated by automated means.

[0077] Separate and Distinct Closing and Firing End Effector

[0078] The end effector 12 of the surgical stapling and severinginstrument 10 is depicted in further detail in FIGS. 10-16. As describedabove, the handle portion 20 produces separate and distinct closing andfiring motions that actuate the end effector 12. The end effector 12advantageously maintains the clinical flexibility of this separate anddistinct closing and firing (i.e., stapling and severing). In addition,the end effector 12 introduces the aforementioned ability toaffirmatively maintain the closed spacing during firing after theclinician positions and clamps the tissue. Both features procedurallyand structurally enhance the ability of the surgical stapling andsevering instrument 10 by ensuring adequate spacing for instances wherean otherwise inadequate amount of tissue is clamped and to enhance theclamping in instances where an otherwise excessive amount of tissue hasbeen clamped.

[0079]FIG. 10 depicts the end effector 12, which is in an open positionby a retracted closure sleeve 32, with a staple cartridge 37 installedin the elongate channel 16. On a lower surface 200 of the anvil 18, aplurality of stapling forming pockets 202 are arrayed to correspond to aplurality of stapler apertures 204 in an upper surface 206 of the staplecartridge 37. The firing bar 14 is at its proximal position, with theupper pin 38 aligned in a noninterfering fashion with the anvil pocket40. The anvil pocket 40 is shown as communicating with the longitudinalanvil slot 42 in the anvil 18. The distally presented cutting edge 48 ofthe firing bar 14 is aligned with and proximally from removed from thevertical slot 49 in the staple cartridge 37, thereby allowing removal ofa spent cartridge and insertion of an unfired cartridge, which issnapfit into the elongate channel 16. Specifically, extension features208, 210 of the staple cartridge 37 engage recesses 212, 214 (shown inFIG. 12) of the elongate channel 16.

[0080]FIG. 11 shows the implement portion 22 of the surgical staplingand severing instrument 10 in disassembled form. The staple cartridge 37is shown as being comprised of a cartridge body 216, a wedge sled 218,single and double drivers 220, staples 222, and a cartridge tray 224.When assembled, the cartridge tray 224 holds the wedge sled 218, singleand double drivers 220, and staples 222 inside the cartridge body 216.

[0081] Having a wedge sled 218 integral to the staple cartridge 37enables a number of flexible design options as compared to incorporatingcamming surfaces onto a firing bar itself. For instance, a number ofdifferent staple cartridges may be selected for use in the instrument 10with each staple cartridge having a different configuration of rows ofstaples, each thus having a unique wedge sled configured to contact themiddle pin 46 of the firing bar 14 while causing the driving of thestaples 222. As another example, the integral wedge sled 218 provides anopportunity for a number of lockout features, described in greaterdetail in the first and third aforementioned co-pending applications.

[0082] The elongate channel 16 has a proximally placed attachment cavity226 that receives a channel anchoring member 228 on the distal end ofthe frame 34 for attaching the end effector 12 to the handle portion 20.The elongate channel 16 also has an anvil cam slot 230 that pivotallyreceives an anvil pivot 232 of the anvil 18. The closure sleeve 32 thatencompasses the frame 34 includes a distally presented tab 234 thatengages an anvil feature 236 proximate but distal to the anvil pivot 232on the anvil 18 to thereby effect opening and closing of the anvil 18.The firing drive member 36 is shown as being assembled from the firingbar 14 attached to a firing connector 238 by pins 240, which in turn isrotatingly and proximally attached to the metal drive rod 140. Thefiring bar 14 is guided at a distal end of the frame by a slotted guide239 inserted therein.

[0083] With particular reference to FIG. 12, a portion of the staplecartridge 37 is removed to expose portions of the elongate channel 16,such as recesses 212, 214 and to expose some components of the staplecartridge 37 in their unfired position. In particular, the cartridgebody 216 (shown in FIG. 11) has been removed. The wedge sled 218 isshown at its proximal, unfired position with a pusher block 242contacting the middle pin 46 (not shown in FIG. 12) of the firing bar14. The wedge sled 218 is in longitudinal sliding contact upon thecartridge tray 224 and includes wedges 228 that force upward the singleand double drivers 220 as the wedge sled 218 moves distally. Staples 222(not shown in FIG. 12) resting upon the drivers 220 are thus also forcedupward into contact with the anvil forming pockets 202 on the anvil 18to form closed staples. Also depicted is the channel slot 45 in theelongate channel 16 that is aligned with the vertical slot 49 in thestaple cartridge 37.

[0084]FIG. 13 depicts the end effector 12 of FIG. 12 with all of thestaple cartridge 37 removed to show the middle pin 46 of the firing bar14 as well as portion of the elongate channel 16 removed adjacent to thechannel slot 45 to expose the firing bar cap 44. In addition, portionsof the shaft 23 are removed to expose a proximal portion of the firingbar 14. Projecting downward from the anvil 18 near the pivot, a pair ofopposing tissue stops 244 prevent tissue being positioned too far upinto the end effector 12 during clamping.

[0085]FIG. 14 depicts the end effector 12 closed in a tissue clampingposition with the firing bar 14 unfired. The upper pin 38 is in theanvil pocket 40, vertically aligned with the anvil slot 42 for distallongitudinal movement of the firing bar 14 during firing. The middle pin46 is positioned to push the wedge sled 218 distally so that wedge 228sequentially contacts and lifts double drivers 220 and the respectivestaples 222 into forming contact with staple forming pockets 202 in thelower surface 200 of the anvil 18.

[0086]FIG. 15 depicts the upper surface 206 of the staple cartridge 37with the firing bar 14 in its unfired, proximal position. The staplerapertures 204 are arrayed on each side of the vertical slot 49 in thestaple cartridge 37.

[0087]FIG. 16 depicts the end effector 12 near the pivot showing thatthe elongate channel 16 has opposing ramp portions 246 to therebycooperate with the tissue stops 244 of the anvil 18 (not shown in FIG.16) to prevent tissue from jamming the end effector 12. Also depicted ingreater detail are the double drivers 220 and their relation to thestaples 222.

[0088] Operation

[0089] In use, the surgical stapling and severing instrument 10 is usedas depicted in FIGS. 1, 2, and 17-23. In FIGS. 1-2, the instrument 10 isin its start position, having had an unfired, fully loaded staplecartridge 37 snap-fitted into the distal end of the elongate channel 16.Both triggers 26, 28 are forward and the end effector 12 is open, suchas would be typical after inserting the end effector 12 through a trocaror other opening into a body cavity. The instrument 10 is thenmanipulated by the clinician such that tissue 248 to be stapled andsevered is positioned between the staple cartridge 37 and the anvil 18,as depicted in FIG. 17.

[0090] With reference to FIGS. 18-19, next, the clinician moves theclosure trigger 26 proximally until positioned directly adjacent to thepistol grip 24, locking the handle portion 20 into the closed andclamped position. The retracted firing bar 14 in the end effector 12does not impede the selective opening and closing of the end effector12, but rather resides within the anvil pocket 40. With the anvil 18closed and clamped, the E-beam firing bar 14 is aligned for firingthrough the end effector 12. In particular, the upper pin 38 is alignedwith the anvil slot 42 and the elongate channel 16 is affirmativelyengaged about the channel slot 45 by the middle pin 46 and the firingbar cap 44.

[0091] With reference to FIGS. 20-21, after tissue clamping hasoccurred, the clinician moves the firing trigger 28 proximally causingthe firing bar 14 to move distally into the end effector 12. Inparticular, the middle pin 46 enters the staple cartridge 37 through thefiring drive slot 47 to effect the firing of the staples 222 (not shownin FIGS. 20-21) via wedge sled 218 toward the anvil 18. The lower mostpin, or firing bar cap 44, cooperates with the middle pin 46 toslidingly position cutting edge 48 of the firing bar 14 to sever tissue.The two pins 44, 46 also position the upper pin 38 of the firing bar 14within longitudinal anvil slot 42 of the anvil 18, affirmativelymaintaining the spacing between the anvil 18 and the elongate channel 16throughout its distal firing movement.

[0092] With reference to FIGS. 22-23, the clinician continues moving thefiring trigger 28 until brought proximal to the closure trigger 26 andpistol grip 24. Thereby, all of the ends of the staples 222 are bentover as a result of their engagement with the anvil 18. The firing barcap 44 is arrested against a firing bar stop 250 projecting toward thedistal end of the channel slot 45. The cutting edge 48 has traversedcompletely through the tissue. The process is complete by releasing thefiring trigger 28 and by then depressing the release button 30 whilesimultaneously squeezing the closure trigger 26 to open the end effector12.

[0093] Single Lockout for Missing/Spent Staple Cartridge

[0094] As described above, the E-beam firing bar 14 provides uniquecapabilities for affirmatively spacing the end effector 12 whilesimultaneously severing tissue and effecting the forming of staples oneach side of the cut. With reference to FIG. 24, preventing the distalmovement of the firing bar 14 thus prevents the inadvertent severing oftissue. A single lockout mechanism 270 advantageously responds to amissing staple cartridge 37 or a spent staple cartridge 37, the lattercondition depicted in FIG. 24, by blocking the middle pin 46 of thefiring bar (only the middle pin of the firing bar being shown in FIG.24).

[0095] In particular, the single lockout mechanism 270 is depicted as apair of bent spring fingers 272 positioned in the elongate channel 16 torespond to both conditions: missing cartridge and spent cartridge. Inparticular, the bent spring fingers 272 raise up to block the middle pin46 of the firing bar 14 when the wedge sled 218 (not shown in FIG. 24)is not present, such as when the cartridge 37 is removed or when thecartridge 37 has been fired.

[0096]FIGS. 25-28 depict the single lockout mechanism 270, specificallythe bent sprint fingers 272 sequentially as the surgical stapling andsevering instrument 10 is fired. In FIG. 25, an unfired staple cartridge37 has been inserted into the elongate channel 16 with the wedge sled218 depressing the bent spring fingers 272 so that the firing drive slot47 formed between the cartridge 37 and the elongate channel 16 isunimpeded.

[0097] In FIG. 26, firing of the cartridge 37 has commenced, with thewedge sled 218 and the middle pin 46 of the firing bar 14 havingdistally traversed off of the bent spring fingers 272, which then springup into the firing drive slot 47.

[0098] In FIG. 27, the staple cartridge 37 is now spent with the wedgesled 218 fully driven distally and no longer depicted. The firing bar 14is being retracted proximally. Since the bent spring fingers 272 pivotfrom a more distal point, the firing bar 14 is able to ride up onto thebent spring fingers 272 during retraction, causing them to be depressedout of the firing drive slot 47.

[0099] In FIG. 28, the firing bar 14 is fully retracted and nowconfronts a non-depressed pair of bent spring fingers 272 to preventdistal movement. The single lockout mechanism 270 thereby activatedremains during the period in which the spent staple cartridge 37 isremoved until an unfired staple cartridge 37 is installed.

[0100]FIG. 29 depicts a lockout trough 274 that may advantageously beincluded in the single lockout mechanism 270 in order to provideincreased mechanical strength. In some applications, it may be desirableto resist strong firing motions without damaging the bent spring fingers272. The lockout trough 274 communicates with the firing drive slot 47when the bent spring fingers 272 are not depressed. Moreover, thelockout trough 274 is downwardly ramped in a distal direction such thatthe middle pin 46 of the firing bar 14 is directed toward an abuttingsurface 276 at a distal end of the lockout trough 274, thereby reactingthe distal movement of the firing bar 14 into an elongate channel 16′.In particular, the firing bar 14 in its initial position moves to adistal and lowered position, depicted at 14′, wherein the middle pin 46moves to a position depicted as 46′. It will be appreciated that theupper pin 38 and lower firing bar cap 44, as each moves to distal andlowered positions 38′ and 44′ respectively, position the middle pin 46against elongate channel 16 so that the middle pin 46 enters the lockouttrough 274.

[0101] It will be further appreciated that the firing bar 14′ may bereadily retracted from the lockout trough 274. Moreover, insofar as theupper pin 38′ would be engaging the anvil 18 (not shown in FIG. 29) inthis position, the clinician would have to retract the firing bar 14′ sothat the anvil 18 could be opened in order to insert an unfired staplecartridge 37, and thus the firing bar 14 would be fully retracted andwould not impede the depressing of the bent spring fingers 272 to theirinactivated position.

[0102]FIG. 30 depicts another single lockout mechanism 270, depicted asa pair of lockout hooks 280 having ramped ends 282 distally placed withregard to attachment devices 284 inserted through apertures 286 in theelongate channel 16. The ramped ends 282 lie above a hook recess 288defined in the elongate channel 16. Thus, when each ramped end 282 iscontacted by a wedge sled 218 of an unfired staple cartridge 37 (notshown in FIG. 30), the ramped ends 282 are depressed into the hookrecess 288, thereby clearing the way for the middle pin 46 of the firingbar 14 (only the middle pin shown in FIG. 30) to move distally to firethe staple cartridge 37. A thin shaft 290 coupling the attachmentdevices 284 to respectively to the ramped end 282 of each lockout hook280 resiliently responds to absence of a wedge sled 218, as depicted,wherein the ramped ends 282 return to impede the firing drive slot 47 toblock a retracted middle pin 46 of the firing bar.

[0103]FIGS. 31-34 depict the sequence of operation of the lockout hooks280. In FIG. 31, the staple cartridge 37 is unfired so that the distallypositioned wedge sled 218 depresses the ramped ends 282 into the hookrecess 288, allowing the middle pin 46 of the firing bar 14 to movedistally during firing, as depicted in FIG. 32. With the wedge sled 218and middle pin 46 distally removed with respect to the lockout mechanism270, the ramped ends 282 resiliently raise out of the hook recess 282 tooccupy the firing drive slot 47.

[0104] In FIG. 33, the firing bar 14 is being retracted to the point ofcontacting the ramped ends 282 of the lockout hook 280. Since the distalend of the ramped ends 282 is lower than the proximal part of the rampedends 282, the middle pin 46 of the firing bar 14 rides over the rampedends 282, forcing them down into the hook recess 288 until middle pin 46is past the ramped ends 282, as depicted in FIG. 34, wherein the rampedends 282 resiliently spring back up to block the middle pin 46. Thus,the firing bar 14 is prevented from distal movement while the spentstaple cartridge 37 is replaced with an unfired staple cartridge 37.

[0105] While the present invention has been illustrated by descriptionof several embodiments and while the illustrative embodiments have beendescribed in considerable detail, it is not the intention of theapplicant to restrict or in any way limit the scope of the appendedclaims to such detail. Additional advantages and modifications mayreadily appear to those skilled in the art.

[0106] For example, a single lockout mechanism may comprise aspring-loaded plunger encompassed within the elongate channel 16 thatmoves upwardly into the firing drive slot 47 when not contacted by thewedge sled 218 with the plunger presenting a hooked or otherwise.

What is claimed is:
 1. A surgical instrument comprising: a handleportion operably configured to produce a firing motion; an elongatechannel coupled to the handle portion; an anvil pivotally attached tothe elongate channel; a staple device engaged by the elongate channeland including a plurality of staple drivers and a wedge member distallypositionable in the staple device to cam the staple drivers toward theanvil; a firing device responsive to the firing motion to drive thewedge member distally; a lockout device disabled by a proximallypositioned wedge member and operably configured to prevent distalmovement of the firing device.
 2. The surgical instrument of claim 1,wherein the staple device comprises a replaceable device.
 3. Thesurgical instrument of claim 1, wherein the staple device includes afiring drive slot through which at least a portion of the firing devicedistally traverses to drive the wedge member, the lockout deviceresiliently intruding into the firing drive slot from the elongatechannel.
 4. The surgical instrument of claim 3, wherein the lockoutdevice presents a surface in the firing drive slot ramped from theelongate channel proximally.
 5. The surgical instrument of claim 4,wherein the lockout device comprises a proximally directed springfinger.
 6. The surgical instrument of claim 5, wherein the elongatechannel includes a recess under the spring finger to receive a portionof the firing device.
 7. The surgical instrument of claim 4, wherein thelockout device comprises a spring-biased plunger.
 8. The surgicalinstrument of claim 4, wherein the lockout device comprises a rampedhook springedly attached to the elongate channel.
 9. A surgicalinstrument, comprising: a handle portion operably configured to producea closing motion and a firing motion; a shaft attached to the handlemotion and operably configured for transferring the closing motion andthe firing motion; an elongate channel attached to the shaft; an anvilpivotally attached to the elongate channel and responsive to the closingmotion; a firing bar coupled to the shaft and responsive to the firingmotion to distally traverse between the elongate channel and the anvil;a staple device engaged by the elongate channel and including a wedgemember displaced by the firing bar during firing; and a lockout devicedisabled by a nondisplaced wedge member.
 10. The surgical instrument ofclaim 9, wherein the staple device comprises a replaceable device. 11.The surgical instrument of claim 9, wherein the staple device includes afiring drive slot through which at least a portion of the firing bardistally traverses to drive the wedge member, the lockout deviceresiliently intruding, into the firing drive slot from the elongatechannel.
 12. The surgical instrument of claim 11, wherein the lockoutdevice presents a surface in the firing drive slot ramped from theelongate channel proximally.
 13. The surgical instrument of claim 12,wherein the lockout device comprises a proximally directed springfinger.
 14. The surgical instrument of claim 13, wherein the elongatechannel includes a recess under the spring finger to receive a portionof the firing device.
 15. The surgical instrument of claim 12, whereinthe lockout device comprises a spring-biased plunger.
 16. The surgicalinstrument of claim 12, wherein the lockout device comprises a rampedhook springedly attached to the elongate channel.
 17. A surgicalinstrument for use through a cannula passageway, comprising: a handlemeans for producing a closing motion and a firing motion; an implementmeans for clamping tissue in response to the closing motion and staplingand severing tissue in response to the firing motion; and a lockoutmeans for preventing severing tissue when the implement means is unableto staple.
 18. The surgical instrument of claim 17, wherein theimplement means further includes an affirmative spacing means forspacing of the tissue clamping during stapling and severing.